1 // Copyright 2013 The Chromium Authors. All rights reserved.
2 // Use of this source code is governed by a BSD-style license that can be
3 // found in the LICENSE file.
4 
5 #ifndef MOJO_EDK_SYSTEM_DATA_PIPE_CONSUMER_DISPATCHER_H_
6 #define MOJO_EDK_SYSTEM_DATA_PIPE_CONSUMER_DISPATCHER_H_
7 
8 #include <stddef.h>
9 #include <stdint.h>
10 
11 #include <memory>
12 
13 #include "base/macros.h"
14 #include "base/memory/ref_counted.h"
15 #include "base/synchronization/lock.h"
16 #include "mojo/edk/embedder/platform_handle_vector.h"
17 #include "mojo/edk/embedder/platform_shared_buffer.h"
18 #include "mojo/edk/embedder/scoped_platform_handle.h"
19 #include "mojo/edk/system/awakable_list.h"
20 #include "mojo/edk/system/dispatcher.h"
21 #include "mojo/edk/system/ports/port_ref.h"
22 #include "mojo/edk/system/system_impl_export.h"
23 
24 namespace mojo {
25 namespace edk {
26 
27 struct DataPipeControlMessage;
28 class NodeController;
29 
30 // This is the Dispatcher implementation for the consumer handle for data
31 // pipes created by the Mojo primitive MojoCreateDataPipe(). This class is
32 // thread-safe.
33 class MOJO_SYSTEM_IMPL_EXPORT DataPipeConsumerDispatcher final
34     : public Dispatcher {
35  public:
36   DataPipeConsumerDispatcher(
37       NodeController* node_controller,
38       const ports::PortRef& control_port,
39       scoped_refptr<PlatformSharedBuffer> shared_ring_buffer,
40       const MojoCreateDataPipeOptions& options,
41       bool initialized,
42       uint64_t pipe_id);
43 
44   // Dispatcher:
45   Type GetType() const override;
46   MojoResult Close() override;
47   MojoResult Watch(MojoHandleSignals signals,
48                    const Watcher::WatchCallback& callback,
49                    uintptr_t context) override;
50   MojoResult CancelWatch(uintptr_t context) override;
51   MojoResult ReadData(void* elements,
52                       uint32_t* num_bytes,
53                       MojoReadDataFlags flags) override;
54   MojoResult BeginReadData(const void** buffer,
55                            uint32_t* buffer_num_bytes,
56                            MojoReadDataFlags flags) override;
57   MojoResult EndReadData(uint32_t num_bytes_read) override;
58   HandleSignalsState GetHandleSignalsState() const override;
59   MojoResult AddAwakable(Awakable* awakable,
60                          MojoHandleSignals signals,
61                          uintptr_t context,
62                          HandleSignalsState* signals_state) override;
63   void RemoveAwakable(Awakable* awakable,
64                       HandleSignalsState* signals_state) override;
65   void StartSerialize(uint32_t* num_bytes,
66                       uint32_t* num_ports,
67                       uint32_t* num_handles) override;
68   bool EndSerialize(void* destination,
69                     ports::PortName* ports,
70                     PlatformHandle* handles) override;
71   bool BeginTransit() override;
72   void CompleteTransitAndClose() override;
73   void CancelTransit() override;
74 
75   static scoped_refptr<DataPipeConsumerDispatcher>
76   Deserialize(const void* data,
77               size_t num_bytes,
78               const ports::PortName* ports,
79               size_t num_ports,
80               PlatformHandle* handles,
81               size_t num_handles);
82 
83  private:
84   class PortObserverThunk;
85   friend class PortObserverThunk;
86 
87   ~DataPipeConsumerDispatcher() override;
88 
89   void InitializeNoLock();
90   MojoResult CloseNoLock();
91   HandleSignalsState GetHandleSignalsStateNoLock() const;
92   void NotifyRead(uint32_t num_bytes);
93   void OnPortStatusChanged();
94   void UpdateSignalsStateNoLock();
95 
96   const MojoCreateDataPipeOptions options_;
97   NodeController* const node_controller_;
98   const ports::PortRef control_port_;
99   const uint64_t pipe_id_;
100 
101   // Guards access to the fields below.
102   mutable base::Lock lock_;
103 
104   AwakableList awakable_list_;
105 
106   scoped_refptr<PlatformSharedBuffer> shared_ring_buffer_;
107   std::unique_ptr<PlatformSharedBufferMapping> ring_buffer_mapping_;
108   ScopedPlatformHandle buffer_handle_for_transit_;
109 
110   bool in_two_phase_read_ = false;
111   uint32_t two_phase_max_bytes_read_ = 0;
112 
113   bool in_transit_ = false;
114   bool is_closed_ = false;
115   bool peer_closed_ = false;
116   bool transferred_ = false;
117 
118   uint32_t read_offset_ = 0;
119   uint32_t bytes_available_ = 0;
120 
121   DISALLOW_COPY_AND_ASSIGN(DataPipeConsumerDispatcher);
122 };
123 
124 }  // namespace edk
125 }  // namespace mojo
126 
127 #endif  // MOJO_EDK_SYSTEM_DATA_PIPE_CONSUMER_DISPATCHER_H_
128